Dental matrix strip



March 26, 1963 R. J. JACOBSON 3,082,531

DENTAL MATRIX STRIP Filed Oct. 23, 1961 Q INVENTOR.

l1 Ro en 27. Jacosazz United States Patent 3,082,531 DENTAL MATRIX STRIPRobert J. Jacobson, 1039A Elm St., Fayetteville, N.C. Filed Oct. 23,1961, Scr. No. 146,805 1 Claim. (CL 32-63) My invention relates todental matrix strips generally, and specifically to a dental matrixstrip including a means for securing it in place.

It is an object of my invention to provide a dental matrix strip forretaining porcelain filling material and the like in a cavity in a toothinto which it is packed.

it is another object of my invention to provide a dental matrix stripwhich is easy to handle, use, apply, and fix in place.

It is yet another object of my invention to provide a dental matrixstrip which conforms to the configuration of the tooth and confines thefilling packed into the cavity.

Yet another object of my invention is to provide a dental matrix stripwhich incorporates self adhering properties by which it secures itselfto teeth adjacent to the tooth being filled.

Yet another object of my invention is to provide a dental matrix stripwhich requires no external aid, either mechanical or manual to maintainit in position during the period in which the filling material is toset. These objects and advantages as well as other objects andadvantages may be attained by the device shown in the drawings in which:

FIGURE 1 is a view in perspective of the inside of a dental matrixstrip.

FIGURE 2 is a top plan view thereof.

FIGURE 3 is a top plan view thereof showing the strip applied to teeth;and

FIGURE 4 is a view in perspective showing the dental matrix strip inoperative position, retaining a filling packed in a cavity, with thestrip secured to an adjacent tooth.

Referring now to the drawings in detail, my dental matrix strip consistsof a band or strip 11, generally rectangular in shape. It may beapproximately two inches long and three-eighths of an inch wide. Thestrip may be formed of a transparent film such as cellophane, althoughthere are numerous other relatively unresilient, water resistant,ilexible materials which will serve just as well. It is preferred thatthe strip or band 11 should be transparent in order that the efiicacy ofits performance and positioning may be determined by visual examination.Thus, when the porcelain filling material is packed into the cavity, thestrip should be applied so as to engage the filling material fromdischarge from the cavity, and the determination of its efiicientfunctioning in this manner can best be arrived at by visual examinationthrough a transparent strip 11.

The means by which the dental matrix strip 11 is held in place is a pairof pads 12 having adhesive qualities. These pads 12 may be approximatelyone-half inch square and one thirty-second to one-sixteenth of an inchthick. The pads are self-sustaining at ordinary temperatures, yet softand flexible and capable of being molded upon the application ofpressure to conform to the surface configuration of a tooth to whichthey are applied with pressure. Material suitable for such rectangularpads 12 "ice which material is workable at room temperature is paraflinwax, beeswax, or spermaceti. These waxes display adhesive properties,and when applied to the strip 11 in the form of a pad 12, will adherethereto. Likewise, the pads 12 will adhere to the teeth to which theyare applied under pressure. A pad 12 is therefore pressed onto the strip11 at opposite ends of the same side of the strip 11, but near the endsthereof. The middle portion 13 of the strip 11 is then wrapped around atooth 14 so that the mid-portion 13 covers a cavity 15 into which afilling 16 has been packed. The cooperative wax pads 12 are disposed onthe side of the strip 11 adjacent to a second tooth 17. Upon applicationof pressure to the strip 11 at the point of the pads 12, the pads aremolded to conform to the external surface of the tooth 17 as shown inFIGURE 3 and adhere thereto. The pads 12 may be rendered more adhesivewith respect to a tooth by mixing the wax with gum damar or any of thesimilar resinous exudates or synthetic resins which display adhesiveproperties. Gum tragacanth will also enhance the adhesive properties ofthe Wax. In addition, a quantity of gum karaya may be sprinkled on thesurface of the pads 12, 12 or kneaded into the wax. Either of thesematerials may also be added in powder form to the melted wax, and thenallowing it to harden. A desiccant is useful to encourage adhesion ofthe wax to moist tooth surfaces. Gum karaya has been found to displaymoisture absorbent properties so that the moist surface of the tooth(which might have a tendency to resist adherence of the pads 12, 12)will be dried and the pads 12, 12 will adhere thereto without anydifficulty. By exerting manual pressure upon the strip 11 it may bebrought into tight engagement with the surface of the tooth 14 adjacentthe cavity 15 so that the filling material 16 is tightly contained untilit sets. There is no necessity for mechanical appliances to retain thestrip in operative position, and a minimum of discomfort is therebyimposed upon the dental patient.

The dental matrix strip is intended primarily for use on interproximalrestorations of anterior teeth i.e. upper and lower centrals, laterals,and cuspids; the teeth shown in the figures are merely intended asillustrative. The dental matrix strip is intended for use with a widevariety of fillings, for example, plastic or silicate fillings and itsuse is not intended to be limited to those mentioned. The thickness ofthe strip should :be of such an order that it may be readily insertedbetween adjacent teeth in the mouth and will yet have the requisitestrength to perform its function of containing a filling. Cellophane andsimilar transparent strip materials have slick surfaces, which areincompatible with the filling materials commonly used in dentistry.Thus, the problem of adherence of the strip to the filling is not acute.

The foregoing description is merely intended to illustrate an embodimentof the invention. The component parts have been shown and described.They each may have substitutes which may perform a substantially similarfunction; such substitutes may be known as proper substitutes for thesaid components and may have actually been known or invented before thepresent invention; these substitutes are contemplated as being withinthe scope of the appended claim, although they are specificallycatalogued herein.

3 4 What is claimed: (e) the band longitudinally dimensioned to wrap Adental matrix strip comprising around a tooth with the pads disposed onopposite (a) a generally rectangular, flexible, relatively thin, id f andj t t th,

non-resilient, moisture resistant transparent band of materialnon-adhesive to dental filling material; 5 References Cited in the fileof this patent (b) a pair of generally rectangular, soft, flexible,self- NITED PA E sustaining, moldable pads of material adherent to USTATES T NTS teeth, the pads adhered to one side of the band; 1,417,091Miner 23, 1922 (c) an adhesive incorporated with the material of the1,550,425 BHIIBW Aug. 18, 1925 d 10 2,196,896 Dvorak Apr. 9, 1940 (d) adesiccant incorporated with the material of the 2,646,622 Christie July28, 1953 pads;

